Oh if you are in CHCH then GOOD NEWS - go to either PhotoWarehouse on Fitzgerald Ave (just up from Lichfield) or go to Photo and Video in Merivale Mall (one of the best stores in the country)
These guys REALLY know their stuff and have an absolute Clue - Hanafins is the same as Harvey Norman or Dick Smith (the one guy who used to have a clue left a couple of years ago)
I've had a good look online at reviews etc but there are so many different ones with different opinions and it all comes down to the fact that the 600D and the D5100 will be excellent starting points and the kit lenses will be sufficient until I outgrow them or decide to take it all further.
From the sentence above it sounds like you have just about got there - I would recommend looking at the costs of the good lenses in the kind of range you want - because when you DO want to to upgrade that will make the difference - if you spend $2k now on either option but its a difference between a $2k lens or a $3k lens it may be a decider.
If you are really stuck I would be happy to catchup and let you have a play with my gear, so you can get a feel for it Im around this weekend